Magnetic storage card

ABSTRACT

When a lower head ( 34   b ) mounted on a lower head arm ( 32   b ) is in a standby position permitting no access to a magnetic recording disk ( 13 ), the lower head arm ( 32   b ) is housed in an opening ( 37 ) formed in a frame plate ( 3 ). Thus, the lower head arm ( 32   b ) and another (upper) head arm ( 32   a ) may maintain a predetermined distance even in a card-type magnetic recording device of small thickness. An electromagnetic shield material is adhered to the opening to protect the heads  34  ( 34   a   , 34   b ).

TECHNICAL FIELD

This invention relates to a card-type magnetic recording device, whichis mounted to a portable computer for input or output of information toor from the computer.

BACKGROUND ART

Insertion of a card-type magnetic recording device in the shape of a PCcard into a slot of a portable computer for supply of information fromthe magnetic recording device to the computer or vice versa permits thecomputer to increase a processing data capacity and also to provideadditional functions.

In such a card-type magnetic recording device, a case body is generallycomposed of a frame, a frame plate formed together with the frame in oneunited body and upper and lower covers for covering the upside and theunderside of the frame plate.

In addition to the frame plate, a circuit substrate mounted withelements on one surface is housed in the case body in the state ofoverlap with the frame plate. A space for housing a cartridge formed byhousing a disk-shaped recording medium (which will be hereinafterreferred to as a disk) in a shell is formed in the case body.

Further, various components such as a recording/reproducing head bodyfor reading and writing information from and to the disk, a drive devicefor swinging a head arm of the recording/reproducing head body, a drivedevice (a motor) for revolving the disk, a lock means for holding thedisk in the case and an ejector mechanism for ejecting the disk towardthe outside of the case are mounted on one surface (the surface on theside of the circuit substrate) of the frame plate.

Most card-type recording devices in general use have dimensions based onPCMCIA standard Type II. According to this standard, dimensions of thecase body of the card-type recording device are regulated to be 54.0 mmin width, 85.0 mm in length and 5.0 mm in thickness.

Thus, a considerable contrivance is required for housing the frame platemounted with various components for recording/reproduction andrevolution of the disk on one surface, together with the circuitsubstrate or the like mounted with the elements on one surface, in thecase body having such a narrow space (a small thickness in particular),while securing a cartridge housing space in the case body.

Further, when the head is not in a disk access position, in other words,the head is placed in a standby position without reading or writinginformation from or to the disk, the head (and the head arm whichcarries the head) is placed distant from the disk in the radialdirection of the disk, and moreover, the head is placed in a locationfurther above the upside of the disk than it is placed in a location forreadout of information from the upper side of the disk, and/or furtherbelow the underside of the disk than it is placed in a location forreadout of information from the underside of the disk.

Thus, it is particularly necessary to take measures to prevent the(upper) head and the head arm from interfering with the other member (anupper cover, for instance) located above the upper head and the headarm, and/or preventing the (lower) head and the head arm frominterfering with the other member (the frame plate, particularly)located below the lower head and the head arm, when the head and thehead arm are in the standby position within the thin case body.

Further, the head for readout and writing of information from and to thedisk is housed in a narrow space in the case body in close proximity toother components, and is therefore easily affected by electromagneticnoise originating from the elements mounted on the circuit substrate ora magnetic field generated from a stator coil as one of constituents ofa disk drive motor, resulting in head reading/writing malfunctions.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to secure a space, which issufficient to permit a magnetic recording/reproducing head mounted on ahead arm to be moved between a recording/reproducing position to obtainaccess of the head to a disk-shaped recording medium loaded in thedevice and a standby position to place the head in a location distantfrom the disk-shaped recording medium without interference of the headwith other members arranged in the device, in a card-type magneticrecording device having dimensions regulated to meet the standard.Another object is to provide a means of preventing the magneticrecording/reproducing head from being affected by electromagnetic noiseand a magnetic field originating from other components or elements closeto each other in a limited space.

To attain the above objects, a card-type magnetic recording deviceaccording to the present invention comprises a disk housing space forhousing a disk-shaped recording medium; a head arm carrying a magneticrecording/reproducing head and causing the magneticrecording/reproducing head to move between a recording/reproducingposition to obtain access to the disk-shaped recording medium loaded inthe disk housing space and a standby position at a distance from thedisk-shaped recording medium; a frame plate which mounts the head armand a disk drive device for driving the disk-shaped recording mediumloaded in the disk housing space, on one surface thereof; and a circuitsubstrate, located on the other surface of the frame plate in overlaparrangement, having a plurality of elements arranged on the surfaceopposite to the surface facing the frame plate; wherein the frame platehas an opening or a concave part allowing the magneticrecording/reproducing head placed in the standby position and/or a partof the head arm to be housed therein. Thus, the magneticrecording/reproducing head can be moved between the standby position andthe recording/reproducing position without interfering with the frameplate.

The opening formed in the frame plate having a thickness of 0.4 mmpermits the magnetic recording/reproducing head placed in the standbyposition to be lowered further by about 0.4 mm. On the other hand, whilethe concave part may be formed in the frame plate by reducing thethickness of a part of the frame plate, the permissible length to lowerthe magnetic recording/reproducing head is limited in this case.However, the concave part formed by projecting the frame plate by meansof drawing or the like increases the permissible length to lower themagnetic recording/reproducing head more than that in the above case.

According to one mode of the card-type magnetic recording deviceaccording to the present invention, the head arm is composed of an upperarm which carries the magnetic recording/ reproducing head to gainaccess to the upside of a disk-shaped recording medium and a lower armcarrying the recording/reproducing head to gain access to the undersideof the disk-shaped recording medium. Then, a part of the lower head armand/or the head mounted on the arm may be housed in the opening or theconcave part formed in the frame plate, and the distance between themagnetic recording/reproducing head mounted on the upper arm and themagnetic recording/reproducing head mounted on the lower arm in thisstate is made wider than the distance between the above magneticrecording/reproducing heads placed in the recording/reproducingposition.

An electromagnetic shield material such as copper foil is adhered to thesurface opposite to the circuit substrate in the frame plate using anadhesive so as to cover the opening. In this case, the copper foil has athickness of about 40 μm, and the adhesive has a thickness of about 30μm.

Instead of forming the opening, a concave part may be formed by reducingthe thickness of a part of the frame plate. The portion having a reducedthickness is also used for the electromagnetic shield material.

Any digital IC is not arranged in a magnetic recording/reproducing headoperation area and its neighborhood area on the circuit substrate, butan analog IC can be arranged in the above areas. Thus, noise originatingfrom the digital IC can be prevented from having an effect on themagnetic recording/reproducing head. The magnetic recording/reproducinghead is hardly affected by the analog IC.

Further, the disk drive device is a motor, and a stator of the motor iscomposed of a plurality of winding parts formed by winding a pluralityof cores with coils. However, a core placed in a location correspondingto the magnetic recording/reproducing head operation area is exposed tothe outside without being wound with a coil. Thus, the magneticrecording/reproducing head can be prevented from being affected bymagnetic noise originating from the winding parts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view showing a card-type magnetic recording devicein the first embodiment according to the present invention;

FIG. 2 is a plan view showing the inside of the card-type magneticrecording device of FIG. 1 with an upper cover removed;

FIG. 3 is a plan view showing a frame plate in the card-type magneticrecording device of FIG. 1 as seen from the outside, together with aframe mounted on the frame plate in one united body;

FIG. 4A is a perspective view showing the frame plate of FIG. 3 as seenfrom the inside;

FIG. 4B is a perspective view showing the frame plate of FIG. 4A as seenfrom the outside;

FIG. 5 is a perspective view (partly in section) for illustrating astructure in which the frame plate of the card type magnetic recordingdevice of FIG. 1 has an opening in a location facing a head standbyposition and this opening is covered with an electromagnetic shield;

FIG. 6 is a sectional view corresponding to the perspective view of FIG.5;

FIG. 7 is a plan view showing a card-type magnetic recording device inthe second embodiment according to the present invention having variousIC elements arranged on the element mounting surface of a circuitsubstrate;

FIG. 8 is a view showing IC elements arrangement as a comparativeembodiment for illustrating effects based on the arrangement of ICelements on the circuit substrate of FIG. 7; and

FIG. 9 is a plan view showing the inside of a card-type magneticrecording device in the third embodiment according to the presentinvention with an upper cover removed.

BEST MODE OF EMBODYING THE INVENTION

A description will now be given of the outline of a card-type magneticrecording device 1 according to the present invention with reference toFIGS. 1 to 4A.

An upper cover 4 and a lower cover 5 are provided as a molded productobtained by pressing a thin SUS plate and are mounted on a frame 2 inone united body by engaging the opposite sides of the covers 4 and 5 tothe frame 2 from outside, providing a case body of the card-typemagnetic recording device 1. The size of the case body, that is,dimensions (width×length×thickness) of the card-type magnetic recordingdevice 1 are based on PCMCIA standard type II to be 54.0 mm in width,85.60 mm in length and 5.0 mm or less in width. Further, each of lowerstage parts 4 a, 5 a at the left and right sides of the upper and lowercovers 4, 5 has a width of not less than 3.0 mm, and a distance betweenthe lower stage part 4 a of the upper cover 4 and the lower stage part 5a of the lower covers 5 is set to be 3.30 mm.

Further, a frame plate 3 is provided as a molded product obtained bypressing a stainless steel plate (SUS plate) and are outsert-moldedtogether with the synthetic resin frame 2 in one united body, providingthe structural and strength foundations of the card-type magneticrecording device 1.

An insulating sheet 10 and a circuit substrate 11 are housed in the casebody, in addition to the frame plate 3.

Various components such as a main ejector mechanism 6, a sub ejectormechanism 9, a magnetic recording/reproducing head body 7 and a diskdrive motor 8 are mounted on the upside of the frame plate 3.

A cartridge 12 having a magnetic recording disk 13 housed therein isinserted into the card-type magnetic recording device 1. Further, thecartridge 12 inserted into the card-type magnetic recording device 1 isejected to the outside of the device through the operation of the mainejector mechanism 6 and the sub ejector mechanism 9.

The lower cover 5 as one of the constituents of the case body has ashutter 14. The shutter 14 is urged by the action of a spring to be heldin a rising state at all times. On the other hand, the shutter 14 fallsdown through forward pivotal motions about the lower end when pressed bythe end of the cartridge 12.

A description will now be given of the frame plate 3 with reference toFIG. 3 showing the underside of the frame plate and FIG. 4A showing theupside thereof.

A cut-out hole 15 is formed at one side (the left side in FIG. 3) of afront part of the frame plate 3, and a mounting hole 15 is formed at theother side (the right side in FIG. 3) thereof. The cut-out hole 15 isused for holding a FPC 61 (see FIG. 2). An upper yoke 17 a, a lower yoke17 b and a stator magnet 18 as constituents of the magneticrecording/reproducing head body 7 (see FIG. 1) are mounted in themounting hole 16.

Further, a concave part 20 for mounting a pivotal axis 21 (see FIG. 2)of the magnetic recording/reproducing head body 7 is formed in the frontpart of the frame plate 3 at an approximately intermediate positionbetween the cut-out hole 15 and the mounting hole 16.

On the other hand, a concave part 19 having a circular cross-sectionalshape for mounting the disk drive motor 8 is formed in a rear part ofthe frame plate 3 by means of drawing, as shown in FIG. 4A. A hole 39for mounting a bearing (not shown) of the disk drive motor 8 is formedin the center of the bottom surface of the concave part 19. Then, aplurality of (18 pieces in FIGS. 3 and 4A) coil mounting slots 38extending from the center of the center hole 39 in a radial directionare formed in the bottom surface of the concave part 19.

The disk drive motor 8 is composed of a stator 45 and a rotor 44. Thestator 45 has radially-extending magnetic cores (not shown) as many as(eighteen pieces) the coil mounting slots 38 in locations around theaxis of rotation of the rotor 44. The eighteen pieces of coil windingparts 45 d are formed by winding each of the eighteen pieces of coreswith coil wires a predetermined number of turns. These coil windingparts 45 d are placed in locations corresponding to the eighteen piecesof coil mounting slots 38 formed in the bottom surface of the concavepart 19.

Further, as shown in FIG. 4A, open holes 36 as many as the coil mountingslots 38 are formed in a peripheral wall 35 of the concave part 19 inlocations corresponding to the middles of the adjacent slots 38 in thebottom surface of the concave part 19. These open holes 36 are forrelief of stress resulting from a process of drawing, and it isnecessary to form the open holes in a material of a flat frame plate 3before being subjected to drawing. Incidentally, each open hole 36 mayextend from the peripheral wall 35 of the motor-mounting concave part 19to the bottom surface of the concave part 19 (to the middle between theadjacent slots 38).

On the other hand, the rotor 44 has a ring-shaped permanent magnet 46,which attracts a hub of the magnetic recording disk 13 housed in thecartridge 12.

Further, various projecting parts functioning as axes and anchor partsof other components mounted on the frame plate 3 are formed on theupside of the frame plate 3.

A description will now be given of the main ejector mechanism 6 and thesub ejector mechanism 9 mounted on the upside of the frame plate 3 withreference to FIGS. 1 and 2.

When the cartridge 12 is inserted into the card-type magnetic recordingdevice 1, the main ejector mechanism 6 locks the inserted cartridge 12in the card-type magnetic recording device 1. On the other hand, whenthe cartridge 12 is again pushed forward a little, the main ejectormechanism 6 releases the cartridge 12 from its locked state to eject thecartridge 12 to the rear.

The main ejector mechanism 6 comprises a cam plate 22, a slider 23, anejector spring 24 and an engagement gear 25. The cam plate 22 issupported on the frame plate 3 in a manner such that it can turn aboutan axis and is urged at all times so that it swings clockwise as shownin FIG. 2. Further, a grooved cam 26 is formed on one surface of the camplate 22, and a gear 27 is formed at the peripheral edge of the camplate 22. A pin 28 at the front end of the slider 23 is engaged with thegrooved cam 26.

When the cartridge 12 is pushed in the card-type magnetic recordingdevice 1 through the opening at the rear, the slider 23 is pressedforward, the main ejector mechanism 6 is locked, and the shutter 14 ofthe cartridge 12 is then opened to thereby permit the magnetic recordingdisk 13 to be loaded in the card-type magnetic recording device 1.

The gear 27 of the cam plate 22 meshes with the engagement gear 25supported on the frame plate 3 in a manner such that it can rotate aboutan axis. The engagement gear 25 also has a projecting portion 29, inaddition to a gear part.

The slider 23 is arranged on the inside of one side (the left side inFIG. 2) of the frame 2 slidably, as shown in FIG. 2.

The sub ejector mechanism 9 has a lever 47 mounted on the frame plate 3so that it can swing about an axis, a first return spring 48 for urgingthe lever to the rear (toward the ejecting direction of the cartridge)and a second return spring (not shown) subjected to accumulation ofenergy when the lever 47 is moved forward, as shown in FIG. 2. The subejector mechanism 9 permits the lever 47 urged by the first returnspring 48 and the second return spring to push out the cartridge 2 tothe rear in cooperation with the main ejector mechanism 6 when thecartridge 12 is released from its locked state.

A description will now be given of the magnetic recording/reproducinghead body 7 mounted on the upside of the frame plate 3 with reference toFIGS. 1 and 2.

The magnetic recording/reproducing head body 7 comprises a resin basebody part 31, a head arm 32, a drive coil 33 and a magneticrecording/reproducing head (which will be hereinafter referred to as ahead) 34 mounted on the end of the head arm 32.

The drive coil 33 and the head arm 32 are respectively fixed to theopposite sides of the base body part 31 in one united body. The magneticrecording/reproducing head body 7 is mounted on the frame plate 3 asbeing freely pivoted about a pivotal axis 21 arranged in the center ofthe base body part 31 (that is, a position of center of gravity of thewhole magnetic recording/reproducing head body 7). A power lead wire(not shown) connected to the drive coil 33 and a signal lead wire (notshown) connected to the head 34 are connected to the base body part 31.

The head arm 32 swings about the pivotal axis 21 so that the head 34moves between a first position A (a standby position shown by a solidline in FIG. 2) where the head 34 is isolated from the magneticrecording disk (hereinafter referred to as disk) 13 in the radialdirection as well as in the direction of disk rotation axis and a secondposition B (a recording/reproducing position shown by a broken line inFIG. 2) where the head comes closer to the surface of the disk 13 inconsequence of movement from the first position A in the radialdirection of the disk 13 as well as in the direction of the diskrotation axis. An angle between the first position A and the secondposition B is about 30 degrees. Further, the head arm 32 slides in theradial direction of the magnetic recording disk 13 to gain access to themagnetic recording disk 13 in the second position B (therecording/reproducing position).

A description will now be given of the circuit substrate 11.

The circuit substrate 11 has a power circuit, an information processingcircuit, and electric elements such as a switching circuit, anamplifying circuit, a CPU and a memory (see FIG. 5) required for theabove power circuit and the information circuit on the base formedmainly by a resin. The circuit substrate 11 is arranged on the undersideof the frame plate 3 through the insulating sheet 10. The insulatingsheet 10 is adapted to eliminate troubles of direct contact of variousprojection parts existing on the upside of the circuit substrate 11 withthe frame plate 3.

The electronic element 41 is arranged on the (underside) surface of thecircuit substrate 11 opposite to the insulating sheet 10. An externalconnection connector 51 meeting PCMCIA standard is mounted on thecircuit substrate 11 along the front edge of the circuit substrate 11.

Power is supplied to the disk drive motor 8 fixed to the motor concavepart 19 of the frame plate 3 through a connector (not shown) provided onthe underside of the circuit substrate 11. A signal from the magneticrecording/reproducing head body 7 of which pivotal axis 21 is fitted tothe axis mounting concave part 20 of the frame plate 3 is given to aconnector (not shown) provided on the underside of the circuit substrate11 through a signal line. Further, power is supplied from a connector(not shown) provided on the underside of the circuit substrate 11 to themagnetic recording/reproducing head body 7 through a power line. Thesignal line and the power line for connection between the circuitsubstrate 11 and the magnetic recording/reproducing head body 7 are puttogether in the FPC 61. A notch part 50 to allow the FPC 61 to pass isformed at one side end of the circuit substrate.

A description will now be given of the first embodiment of the presentinvention in more detail with reference to FIGS. 4B to 6.

In the first embodiment, the head arm 32 is composed of an upper arm 32a gaining access to the upside of the magnetic recording disk 13 and alower arm 32 b gaining access to the underside of the magnetic recordingdisk 13. Thus, the heads 34 are mounted on the upper arm 32 a at the endthereof and also on the lower arm 32 b at the end thereof, respectively,as shown by reference numerals 34 a, 34 b.

FIGS. 5 and 6 show the state where the upper arm 32 a and the lower arm32 b as constituents of the head arm 32 together with the heads 34 a, 34b mounted to the ends of the arms 32 a, 32 b are in a standby position(corresponding to the position A in FIG. 2). These arms and heads in therecording/reproducing position (corresponding to the position B in FIG.2) are shown in FIGS. 5 and 6 by putting “′” on the correspondingreference numerals for indicating that they are positioned in arecording/reproduction position. That is, in FIGS. 5 and 6, the arm 32′(the upper arm 32 a′ and the lower arm 32 b′) and the heads 34 a′ and 34b′ mounted on the ends of the arms 32 a′, 32 b′ indicate that they thesearms and heads are positioned in the recording/reproducing position.

As is apparent from FIGS. 5 and 6, the distance between the upper arm 32a and the lower arm 32 b on standby (or between the heads 34 a and 34 bon standby) is made wider (in an open state) than the distance betweenthe upper arm 32 a′ and the lower arm 32 b′ in process ofrecording/reproduction (or between the heads 34 a′, 34 b′ on standby).This is because considerations are made to move the head arm 32 onstandby to the recording/reproducing position by taking the actions oflowering the upper arm 32 a from a position above the magnetic recordingdisk 13 toward the upside of the magnetic recording disk 13, whileraising the lower arm 32 b from a position below the magnetic recordingdisk 13 toward the underside of the magnetic recording disk 13.

An opening 37 (see FIG. 4A) for housing the lower arm 32 b and the head34 b mounted; on the end of the lower arm 32 b is formed in the frameplate 3 such that the upper and lower arms 32 a, 32 b placed in the openstate in the standby position can be housed in the card-type magneticrecording device 1 having the dimensions regulated to meet PCMCIA TypeII standard.

As a result, when the head arm 32 is in the standby position, the end ofthe lower arm 32 b is housed in the opening 37 formed in the frame plate3 without being placed on the frame plate 3, as shown in FIG. 6. Inconsequence, the head arm 32 can hold its open state in the card-typemagnetic recording device 1 having a thickness regulated to meet theabove standard.

In movement of the head 34 placed in the standby position to therecording/reproducing position, the upper arm 32 a and the lower arm 32b as constituents of the head arm 32 moves to the positions (therecording/reproducing positions) shown by reference numerals 32 a′, 32b′ in FIGS. 5 and 6, while being guided by a guide mechanism (not shown)in a direction of coming closer to the magnetic recording disk 13 asshown by dotted lines with arrows in FIGS. 5 and 6.

While the opening 37 is formed in the frame plate 3 to eliminate theinterference of the lower arm 32 b of the head arm 32 with the frameplate 3 as shown in FIGS. 5 and 6, a concave part may be formed, insteadof the opening 37, if a reduction in thickness of a part of the frameplate 3 (that is, formation of the concave part) makes it possible toprevent the lower arm 32 b from interfering with the frame plate 3. Asdescribed above, either forming an opening in the frame plate 3 or aconcave part by locally reducing the thickness of the frame plate canprevent the head arm 32 from interfering with the frame plate 3.

When the opening 37 is formed in the frame plate 3, the electromagneticnoise originating from the electronic element 41 mounted on the circuitsubstrate 11 arranged on the underside of the frame plate 3 through theinsulating sheet 10 reaches the head 34 (34 a, 34 b) placed in thestandby position through the opening 37 and as a result, has an effecton the head. To avoid the above situation, it is necessary to cover theopening 37 formed in the frame plate 3 with an electromagnetic shieldmaterial 40 adhered to the underside of the frame plate 3 with anadhesive, as shown in FIG. 4A. Since the opening 37 of the frame plate 3is covered with the electromagnetic shield material 40, theelectromagnetic noise originating from the electronic element 41 mountedon the circuit substrate 11 may be restrained from reaching the head 34(34 a, 34 b) through the opening 37.

Incidentally, the electromagnetic shield material 40 may extend towardthe concave part 19 for mounting the disk drive motor, formed in theframe plate 3, to cover one or more (two in the embodiment in FIG. 4B)open holes 36 near the head 34 (34 a, 34 b) among the eighteen pieces ofopen holes 36 formed in the peripheral wall of the concave part 19, asshown in FIGS. 4B, 5 and 6. Also, the electromagnetic shield material 40may extend therefrom to cover one or more (two in the embodiment in FIG.4B) coil mounting slots 38 near the head 34 (34 a, 34 b) among theeighteen pieces of coil mounting slots 38.

FIG. 4B shows an embodiment wherein an electromagnetic shield material40 a for covering the open holes 36, the electromagnetic shield material40 for covering the opening 37 and the electromagnetic shield material40 for covering the coil mounting slots 38 are formed in one unitedbody. Instead of this structure, the above electromagnetic shieldmaterials 40 may be formed individually.

As has been described above, the card-type magnetic recording device 1according to the first embodiment of the present invention makes itpossible to prevent the head arm 32 and the head 34 placed in thestandby position from interfering with the frame plate 3 within thecard-type magnetic recording device having a limited thickness, byforming the opening 37 in the part of the frame plate 3 or forming theconcave part instead of the opening 37.

Further, the opening 37 formed in the frame plate 3 is covered with theelectromagnetic shield material 40 so that the influence of theelectromagnetic noise, originating from the circuit substrate 11 andpassing through the opening 37, on the head 34 can be reduced.

Further, the coil mounting slots 38 formed in the frame plate 3 forarrangement of the stator coil 45 and the open holes 36 formed in theframe plate 3 for relief of stress resulting from a process of drawingfor formation of the motor mounting concave part 19 may be covered withthe electromagnetic shield material 40 a, so that the influence of thenoise, originating from the circuit substrate and passing through theslots 38 and the open holes 36, on the head 34 can be reduced.

A description will now be given of the outline of a card-type magneticrecording device 1 in the second embodiment according to the presentinvention with reference to FIGS. 7 and 8.

As shown in FIG. 7, a connector 70 connected to a connector terminal 62(see FIG. 2) formed at the end of the FPC 61 is mounted on the circuitsubstrate 11 in the proximity of a notch part 50. Further, essential ICssuch as a read circuit analog IC 81, a motor drive IC 82 for controllingdrive of the disk drive motor and the drive motor of the magneticrecording/reproducing head body 7, a logic IC 83 for converting a modeof a signal to and from external information equipment (not shown), alogic IC 84 for supporting the deficient functions of the logic IC 83, aMPU and a logic IC 85 for controlling the whole motions of the magneticrecording disk 13 for recording, reproduction and driving, a memory IC86 for storing the basic software and a power supply IC 87 are mountedon the circuit substrate 11.

Among the above essential ICs, the read circuit analog IC 81 and themotor drive IC 82 are analog ICs, while the logic ICs 83, 84, the MPUand logic IC 85, the memory IC 86 and the power supply IC 87 are digitalICs,.

An imaginary line in FIG. 7 shows that the head 34, which is arrangedabove the circuit substrate 11, moves within an operation area betweenthe first position A (corresponding to the position A in FIG. 2) and thesecond position B (corresponding to the position B in FIG. 2).

As shown in FIG. 7, it is a features of the second embodiment thatconsiderations are made not to arrange any digital ICs in the operationarea of the head 34 on the circuit substrate 11. This is because currentsupplied to the analog IC (ICs 81, 82) is several mV, whereas currentsupplied to the digital IC (ICs 83 to 87) is in the range of 0 to 5V,with the result that noise originates from the digital IC exclusivelyand has an effect on the head 34.

Thus, if the arrangement of the essential ICs (ICs 81 to 87) is made asshown in FIG. 8, the noise originating from the logic IC 84 provided asthe digital IC arranged in the operation area of the head 34 has aneffect on the head, resulting in occurrence of errors in recording andreproduction to and from the magnetic recording disk 13.

In FIG. 7, the read circuit analog IC 81 is arranged in the operationarea of the head 34 on the circuit substrate 11. This is because the IC81 is an IC which operates in response to a feeble signal, andtherefore, is affected by the noise if the IC 81 is arranged distantfrom the connector 70 to make a wiring pattern longer. For that reason,the IC 81 needs to be arranged close to the connector to prevent the IC81 from being affected by the noise as much as possible.

As has been described above, the card-type magnetic recording device 1in the second embodiment according to the present invention makes itpossible to prevent the noise originating from the digital ICs fromhaving an effect on the head 34 by arranging the digital ICs on thecircuit substrate 11 outside the operation area of the head of themagnetic recording/reproducing head body. The analog ICs may be arrangedin the operation area of the head 34 of the magneticrecording/reproducing head body on the circuit substrate 11.

A description will now be given of the outline of a card-type magneticrecording device 1 in a third embodiment according to the presentinvention with reference to FIG. 9.

In the above card-type magnetic recording device 1 shown in FIG. 2, thehead 34 may be affected by the magnetic noise originating from onewinding part 45 d located close to the head 34 placed in the position B(the recording/reproducing position) in FIG. 2 among eighteen pieces ofwinding parts 45 d forming the stator of the disk drive motor, resultingin hindrance of normal writing and readout operations.

For avoiding the above problem, it is well-known to project a flangefrom a member which supports a stator of a motor for driving a magneticrecording disk so as to separate the stator from the magnetic disk (andthe magnetic head) and then adhere a magnetic shield thin plateconsisting of a material of high magnetic permeability to thestator-side surface of the flange, forming a closed magnetic circuitwith the stator, a rotor magnet facing the stator, a rotor holder forholding the rotor magnet, the stator and the flange. (Refer to JapaneseUtility Model Publication No. 2-2066) However, the well-known techniquehas a disadvantage in that the magnetic shield thin plate consisting ofthe material of high magnetic permeability is expensive, and much laboris required for adhering the magnetic thin plate to a predeterminedposition of the flange.

According to the third embodiment, the problems with the above prior artare dissolved by providing a non-winding part C formed by winding nocoil around one core 45 e located close to the head 34 placed in therecording/reproducing position (the position B of FIG. 9) to expose thecore 45 e to the outside.

In FIG. 9, the head arm 32 makes swing motions about the pivotal axis 21between the standby position (the position A shown by a solid line inFIG. 9) where the head 34 mounted on the end of the head arm takesretreat from the disk area and the recording/reproducing position (theposition B shown by a broken line in FIG. 9) where the head 34 comescloser to the surface of the magnetic recording disk 13 for recordingand reproduction, similarly to the head arm shown in FIG. 2.

Even if one of eighteen pieces of winding parts 45 d forming the stator45 of the disk drive motor 8 is made non-winding part C, driving of thedisk drive motor 8 is hardly influenced.

According to the third embodiment, since the head may be protected fromthe influence of the magnetic noise originating from the winding parts45 d only by winding no coil around one of a plurality of cores, it ispossible to provide a magnetic recording device which is available at alow cost and has a higher reliability in comparison with the prior artdescribed above.

What is claimed is:
 1. A card-type magnetic recording device comprising;a disk housing space for housing a disk-shaped recording medium; a headarm carrying a magnetic recording/reproducing head and causing themagnetic recording/reproducing head to move between arecording/reproducing position to obtain access to the disk-shapedrecording medium loaded in said disk housing space and a standbyposition at a distance from the disk-shaped recording medium; a frameplate which mounts said head arm and a disk drive device for driving thedisk-shaped recording medium loaded in said disk housing space, on onesurface thereof; and a circuit substrate, located on the other surfaceof said frame plate in overlap arrangement, having a plurality ofelements arranged on the surface opposite to the surface facing saidframe plate; wherein said frame plate has an opening or a concave partallowing the magnetic recording/reproducing head placed in said standbyposition and/or a part of the head arm to be housed therein, allowingthe magnetic recording/reproducing head to move between the standbyposition and the recording/reproducing position without interferencewith said frame plate.
 2. A card-type magnetic recording deviceaccording to claim 1, wherein said head arm is composed of an upper armcarrying the recording/reproducing head to gain access to the upside ofthe disk-shaped recording medium, and a lower arm carrying therecording/reproducing head to gain access to the underside of saiddisk-shaped recording medium, the part of the lower head arm and/or thehead mounted on the arm is housed in the opening or concave part formedin the frame plate, and the distance between the magneticrecording/reproducing head mounted on the upper arm and the magneticrecording/reproducing head mounted on the lower arm in this state ismade wider than the distance between said magnetic recording/reproducingheads placed in the recording/reproducing position.
 3. A card-typemagnetic recording device according to claim 1, wherein said opening isclosed with an electromagnetic shield material by adhering it to thesurface of the frame plate on the side opposite to the circuitsubstrate.
 4. A card-type magnetic recording device according to claim1, wherein an electromagnetic shield material is provided to close anopen hole for relief of stress resulting from a process of drawing forformation of coil mounting slots in the frame plate for arrangement of astator coil and/or a motor mounting concave part in the frame plate, onthe side of the circuit substrate.
 5. A card-type magnetic recordingdevice according to claim 1, wherein an electromagnetic shield materialis adhered to the surface of the frame plate opposite to the circuitsubstrate to cover said opening, and another electromagnetic shieldmaterial is provided, integral with the electromagnetic shield material,to close an open hole for relief of stress resulting from a process ofdrawing for formation of coil mounting slots in the frame plate forarrangement of the stator coil and/or a motor mounting concave part inthe frame plate, on the side of the circuit substrate.
 6. A card-typemagnetic recording device according to claim 3 or 4, wherein saidelectromagnetic shield material is made of copper foil.
 7. A card-typemagnetic recording device according to claim 1, wherein a reducedthickness portion obtained by forming said concave part in the frameplate also serves as an electromagnetic shield material.
 8. A card-typemagnetic recording device according to claim 1, wherein digital ICs arearranged on the circuit substrate in an area other than an operationarea from the recording/reproducing position to the retreat position andits neighborhood area, without arranging any digital ICs on the circuitsubstrate in the operation area of said magnetic recording/reproducinghead and its neighborhood area.
 9. A card-type magnetic recording deviceaccording to claim 8, wherein analog ICs are arranged on the circuitsubstrate in the operation area of said magnetic recording/reproducinghead and its neighborhood area.
 10. A card-type magnetic recordingdevice according to claim 8, wherein said disk drive device is a motorprovided with a stator having a plurality of winding parts formed bywinding a plurality of cores with coils and a rotor driven by arevolving magnetic field generated in said stator, and the core or coreslocated in the operation area of said magnetic recording/reproducinghead from the recording/reproducing position to the retreat position andits neighborhood area, among the plurality of cores, are not wound withcoils.
 11. A card-type magnetic recording device according to claim 10,wherein said core is made of a magnetic material and is formed toarrange radially about the axis of rotation of said rotor, and the coreor cores wound with no coil, among said cores, are exposed to theoutside.